1. Field of Use of the Invention
The invention relates to a climbing robot for travelling over adhesive surfaces of nearly any desired geometry. Adhesive surfaces are intended to be understood as surfaces on which suction elements and/or magnetic elements could adhere. The geometry of the adhesive surfaces could be both flat and curved; it could extend in a flat, tilted or vertical fashion and could have small obstacles.
2. Prior Art
The use of automatic climbing devices that develop their holding power via magnetism or via a vacuum is known for movement on vertical or tilted adhesive surfaces; the term “vacuum” stands, strictly speaking, for underpressure. With regard to the type of movement, a distinction is made between walking gear and running gear. Both are especially designed for flat adhesive surfaces.
Walking gear only achieves working speeds of up to 3 m/min. at present. The movement takes place on a periodic basis with stops. Half of the suction cups have to be released, raised and moved ahead to achieve working speeds of 3 m/min. After that, these suction cups are lowered and the suction is applied. Subsequently, the remaining suction cups have to follow up with the same procedure. The available holding power will consequently continually vary between 50% and 100%.
If the suction cups are moved ahead or if they follow up in pairs or individually, the movement speed drops to well under 3 m/min. The high level of control and monitoring complexity for the individual movements is likewise a disadvantage. An advantage of devices of this type is the maneuverability, which can be simply realized via a lateral displacement crosswise to the direction of movement, and the ability that the device has right from the start to overcome small obstacles such as strips. Walking devices are described, for instance, in DE 24 58 491 A1, DE 198 35 03801, DE 199 07 437 A1, EP 0 401 120 A1, U.S. Pat. No. 4,674,949 A, U.S. Pat. No. 5,551,525 A, and U.S. Pat. No. 6,105,695 A.
Running gear achieves higher working speeds of up to 10 m/min. The movement is uniform without stops, and the work cycles—releasing adhesive elements, lifting, follow up, lowering and suction application—can simultaneously take place for the relevant adhesive elements. The holding power that is continually available consequently varies between 80% and 100%. The low level of control complexity is also advantageous, since the work cycles can be run with positive control. The inadequate maneuverability, such as a lateral displacement crosswise to the direction of movement, and the lacking capability in the base mechanism to overcome small profile sections or similar obstacles in vertical walls are drawbacks in the known running gear. Examples of crawlers with suction elements are in DE 35 40 432 A1, DE 197 27 421 C2, DE 101 40 990 A1, DE 296 22 167 U1, EP 0 505 956 A1, EP 584 520 B1, EP 1 792 673 A2, U.S. Pat. No. 5,487,440 A and U.S. Pat. No. 6,090,221 A, and those with magnetic elements are in EP 0 248 659 A2, EP 0 716 006 A2, EP 0 812 758 B1, EP 1 650 116 A1 and WO 2007/025553 A1.
With regard to the running gear, the crawler technology is the most practical solution at present.
The circulating endless traction mechanisms, such as chains, bands, cables or belts, that are in place to realize the movement, still have to be equipped with adhesive elements, however, and thus suction cups or magnets.
The principle is based on the fact that every adhesive element attached to an endless traction mechanism runs through an endless loop. The adhesive elements turned towards the running surface are actuated, and they hold the running gear to the adhesive surface. If the endless traction mechanisms are put into motion, the rear adhesive elements have to be switched “OFF” in each case so that they can be released from the adhesive surface and the endless traction mechanisms can swivel these adhesive elements upwards by 180°. The swiveled-around adhesive elements will consequently point in the direction turned away from the adhesive surface. The adhesive elements are transported in the direction of travel in that position and will be swiveled once again by 180°, whereupon they will be turned towards the adhesive surface again. The adhesive elements are now switched “ON” and can secure the running gear to the adhesive surface. After the running gear has gone past the adhesive elements that are switched “ON”, they will be switched “OFF” once again and swiveled. This process continually repeats itself during travel for each individual adhesive element.
A drawback of the crawler technology is the fact that it can hardly overcome curved surfaces and profile sections. In addition, only very small adjustment maneuvers can be carried out. They also have a large overall height based on the design, because the adhesive elements go back overhead.
A robot based on crawler technology is known from EP 0 710 188 B1 with suction elements that go back overhead that is designed to travel over the outer skin of an aircraft in order to carry out inspection, cleaning or polishing work.
Thus, the robot likewise has a very high design, which interferes with its tipping-related stability in tilted areas or vertical areas.
A climbing robot based on crawler technology is known from DE 102 12 964 A1; its suction feet are mounted and routed according to the paternoster principle in such a way that their suction surfaces are nearly aligned in parallel with the surface. Details are not disclosed.
Finally, an automatic climbing mechanism for facades, especially glass facades, is described in EP 1 507 696 B1, which was used to form the preamble of the main claim; it likewise operates based on crawler technology, but its endless traction mechanisms equipped with adhesive elements circulate in the travel plane, which is why the adhesive sides of the adhesive elements always point towards the adhesive surface. The mechanism is very flat because of that. It can travel over tilted, vertical and overhanging walls, lift small loads and climb over facade profiles at a low height. It has a pair of endless traction mechanisms. The adhesive elements that support and move the running gear are switched “ON” and adhere to the adhesive surface; all of the others are lifted and switched “OFF”. The chain pairs are run in straight, longitudinal sections that are parallel to one another and run back in an arc. The holding power during the work of a robot that is used is consequently dependent upon the length of the running gear. The running gear has to have an appropriate length. The steering maneuvers are more complex, because the running gear has to be rotated before the travel can be continued for a 90° turn. Furthermore, the running gear is not capable of traveling over curved surfaces, because the rigid, long frame cannot follow the curving profile of a surface.